We have 24 pounds of apaches tears that I collected in Nevada. We have been working at polishing them, but having lots of problems. The early tumbling stages went fine. My wife used a combo pack of polishing media that she bought on eBay. This is what we believe we used:
Course grit (70 Grit Aluminum Oxide)
Fine grit (220 Grit Aluminum Oxide)
Pre polish (500/600 Grit Silicon Carbide)
Polish (diatomaceous earth)
The polish was unlabelled, but we found out after the fact that the polish was diatomaceous earth.
Everything seemed to go fine up to the polish stage. The apache tears/obsidian came out looking worse than they went in. The diatomaceous earth worked awful on the apache tears/obsidan.
My wife put them back in for the pre-polish stage, and they came out looking better. So we tried to polish them again. This time we used cerium oxide. Again, the apache tears/obsidian came out looking worse than they went in. Not nearly as bad as what the diatomaceous earth did though.
Here is a picture of what the rocks looked like before (left) and after (right) the cerium oxide polish stage.
So we are going to try again. We have read that we probably want to use some sort of filler to buffer the rocks and slow down the polishing. This time we are polishing them with cerium oxide & plastic beads.
On my last trip to Nevada, I stayed with my father in Pahrump. My father and I took a day trip out towards Scotty’s Junction, and collected close to 25 pounds of Apache tears alongside the road. I boxed them up and mailed them back to my wife. My wife is working on polishing some of those. On her first attempt she used one barrel of our dual barrel Lortone rock tumbler. Things were looking very good up to the final polishing stage. She put the Apache tears in the final polishing stage, left them in for a week. They looked worse after the final polishing stage than they did going in. We are not sure what went wrong. We’re thinking that the polishing medium was not correct. I am not positive as to what exactly the polishing medium was, as it came in a bag and was not marked as to what exactly it was. My wife got it off of eBay a year ago. I contacted the eBay seller who my wife thinks she ordered the polish from. He said the polish is diatomaceous earth. I searched, and found diatomaceous earth is a good polish for metals. So if the polish we used was in fact diatomaceous earth, it’s apparently not good for polishing obsidian. We have ordered some new polishing medium. We ordered a couple different kinds, both recommended for obsidian. One of the mediums is red rouge, and the other is cerium oxide. The red rouge is cheaper, so I hope it does a good job.
After the first batch didn’t work out as well as we hoped, my wife started a new batch. This time she used our large 15 pound Lortone tumbler. She started off a whole new batch of rocks. She figured that after those have gotten polished down, she would combine in previous batch into the second or third stage. We just pulled out the rocks on Sunday, and most of the rocks look excellent. However the large Apache tears, say the size of a golf ball or larger, didn’t seem as well polished as the smaller Apache tears. Our plan is to pull out the larger stones and set them aside for now. When the new polishing medium comes, we will take some of the smaller stones and put them in for the final polishing stage into one or two barrels of the dual barrel Lortone rock tumbler. Maybe we can try one polishing medium in one barrel and the other polishing medium in the other barrel. Then we can compare the results.